Blowing-engine or compressor.



G. MESTA.

BLOWING ENGINE 0R COMPRESSOR.

APPLICATION FILED AUG. 4, 1909.

958,705. Patented May 17, 1910.

3 SHEETS-SHEET 1.

i 21 K 2s 4 25 Oil 34 T2 1 2 -v3() i 28 33 WITNESSES I NVENTOR G. MESTA.BLOWING ENGINE 0R COMPRESSOR.

APPLICATION FILED AUG.4, 1909.

958,705. Patented May 17, 1910.

3 SHEETS-SHEET 2.

F I I 2- I 14 17 7 7 8 15 16"- Jsa 16 16 WITNESSES INVENTOB t W f? G.MESTA.

BLOWING ENGINE 0B. COMPRESSOR.

ATPLIOATION FILED AUG. 4, 1909.

Pafien ted May. 17, 1910.

3 SHEETS-SHEET 3.

'II/IIIIII4 I NVENTOR wf WITNESSES UNITED STATES PATENT i OFFICE- GEORGEMESTA, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO MESTA MACHINE COMPANY, OFPITTSBURG, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

BLOWING-ENGINE. 0R COMPRESSOR.

Specification of Letters Patent.

Patented May 17, 1910.

Application filed August 4, 1909. Serial No. 511,191.

drawings, forming part of this specification,

in which Figure 1 is a view partly in side elevation and partly insection of a portion of a blowing engine embodying my invention, showingthe engine piston at-the limit of one of its compression strokes; Fig. 2is a View showing one end portion of the engine in section and the otherend portion in side elevation with the piston at an intermediate pointin its return stroke; Fig. 3 is a view partly in elevation and partly insection; and Fig. 4 is a plan view of one of the combined inlet andoutlet valves removed.

My invention has relation to blowing engines or compressors, and moreparticularly to improved valve mechanism therefor. In this art, highspeed is becoming more and more important in order to reduce the costperunit of output. high speed, two features are of primary importance:first, large areas through the inlet and outlet valves, together withsmall clearance volumes; and, second, reliability and absence of shocksin the movement of the valves.

My invention relates to that type of compressor in which smoothness ofvalve motion is obtained by interposing a positively actuated valvebetween the compressor cylinder and the puppet discharge valves. Thisgeneral arrangement of parts has in itself been known since as early as1885, and is, therefore, not claimed by me as an invention; but myinvention is an improvement on this type of compressors, whereby theefliciency of the same is increased, particularly for use as blowingengines.

As before stated, large inlet and outlet areas and small clearances areessential. I obtain this combination of features by utilizing bothhalves of each cylinder head for the ports, and using the same ports inpart for both inlet and outlet. To minimize clearance and frictionlosses, I extend the outlet port between the cylinder and puppet Inorder to secure a v3 and 4 the cylinder heads.

valve straight through the positively actuated valve; thereby obviatingchange of di- I'QCtlOILiIl the flow of the air between the cylinder andthe puppet valve. In order to further reduce friction and clearancevolume, I increase the ratio of the width of theports in the outletvalve to the diameter of the same valve in a much greater extent thanever heretofore attempted. As a result of this, the valve'when opened tothe atmosphere or to the inlet passage is supported upon only a verysmall portion ofits periphery. This has a tendency to deform the. valveandcause binding, wear and more or less rapid destruction. To overcomethis difiiculty, and at the same time to provide ,free and gnobstructedflow through the valve, I provide the latter with circumferential ribsor flaps, which act to extend the bearing for the valve and form asupport therefor in the middle of its otherwise unsupported span, untilsuch time as the valve is turned far enough to increase the extent ofits natural support beyondthe port.

All positive operating means are more or less subject to misadjustment.In blowing engines, quick stoppage for repairs is not feasible, and ifthe rotary valve is not properly adjusted, slamming of the dischargevalves will occur. To prevent breakage under these conditions, I employa discharge valve having dash-pot means which cushion the valve duringboth its opening and closing motions.

The precise nature of my invention and the manner in which the foregoingand other minor objects are attained will be best understood byreference to the accompanying drawings, which will now be described andwhich illustrate the preferred embodiment of my. invention, it beingpremised, however, that various changes may be made in the details ofconstruction and arrangement of the parts, without departing from thespirit and scope of my invention, as defined in the appended claims.

,In these drawings, the numeral 2 designates the tub or cylinder of theengine, and K 5 designates the engine piston, and 6 the piston rod.

The two heads 3 and 4, together with the arrangement of inlet anddischarge ports and valves now to be described, are preferably the sameat both ends of the cylinder,

and the description will therefore be confined to the construction andarrangement at one end and similar reference characters will be appliedto corresponding parts at the opposite end.

Each head is provided with the inlet chambers 7, which are supplied bythe inlet ports 8 and which communicate wlth the end of the cylinderthrough the ports 9, which extend transversely through'the inner wall 10of the cylinder head. outlet chamber or passage which communicates withthe ports 9, through the ports or passages 12,- and through theautomat1c d1scharge valves 13 and the combined inlet and auxiliarydischarge valves 14. The valves 14 are of the rotary cylindrical type,being mounted'in the cylindrical cages or seats 15. Each of these valveshas a cut away portionor port 16, which is designed in one position ofthe valve to connect the port 9 with the inlet chamber 7, and also aport 17, which, in the other position of the valve, is designed toconnect the port 9 with the space or chamber 12, between the valve 14and the automatic discharge valve 13. The two valves 14 are arrangedside by side to control the respective ports 9, and a plurality, in thepresent instance four, of the automatic discharge valves 13 are employedin connection with each of the valves 14. The stems 18 of the valves 14,are extended exteriorly of the heads at one end and are provided withthe rocker arms 19, connected to the actuating rods 20, which areconnected to the straps of the usual eccentrics on the engine shaft.Each of the rods 20 is connected to one of the valves at each end of thecylinder, the two rods being arranged side by side and actuated inunison. Each of the valves 14, is, in accordance with my invention,provided stone of the edges of the inlet port 16, with one or moreprojecting lips or flaps 16, extending into said port.

As shown in detail in Fig. 4, the valve body preferably has continuousend bearing surfaces 16" and a continuous central bearing surface 16. Ipreferably arrange one or more of the lips orflaps 16 between thecentral bearing surface 16 and each end bearing surface 16. By referenceto Figs. 1 and 2, it will be readily seen that these lips or flaps actto increase the support of the valves against the force of the blastpressure at the time when they are just opening to the atmosphere, andbefore they have turned sufliciently far to have their. full naturalsupport. This feature greatly strengthens the valves and preventsbinding and Wear thereof,

The automatic discharge valves 13 are puppet valves and while they maybe of various forms, .I prefer to construct and arrange themsubstantially in the manner 11 designates theshown in the drawings. Asthey are shown, each of these valves consists of a valve disk or plate21, arranged to 'seat on the ring 22 v largement constituting a pistonchamber 29,

the piston disk 30 bein secured to the valve rod or stem within saichamber. A spring 31 is seated at one end against the piston' disk andat its opposite end against the inner v end of the sleeve 28. The s acein the chamber 29, above the piston 30 is formed with a vent or outlet32, controlled by a valve33, and the space below the piston is providedwith a similar vent or outlet 34, controlled by a valve 35. v

The operation is as follows: With the parts in the position shown inFig. 1, the piston 5 has ust completed its com ression stroke in onedirection,-and the va ves 14, at that end of the cylinder, have beenturned in the position shown in Fig. 1, to close the orts 9,'said valvesmovin in the direction Indicated by the arrow. t will be noted that inthis position of the valve, comressed air at receiver pressure istrapped n the spaces or chambers 12, between the valves 13 and 14,thereby subjectin both sides of the valves 13 to substantially the ofthe engine piston from the valve. This fact, as is known to thoseskilled in the art, permits the use of very light springs 31, forclosing the valves 13, it being necessar that such springs shall havejust su cientstrength to overcome the very slight-friction of thevalves.

maintain the ports closed during the return stroke of the piston anduntil the piston again starts on its next stroke, it will be .105 samepressure in spite of the rapid receding Inasmuch as the auxil- Y iaryvalves 14, when properly adjusted, will readily seen that the valves 13can close clearance spaces at the ends of the cylinder, and these portsbeing extremely short, there is very litt e air left therein tobereexpanded intothe cylinder at the beginning of the inlet stroke. Thevalves 14 bein closed at the beginning of this stroke an until thepiston has moved sufiiciently far to expand the air in the ports 9 tosubstantially atmospheric pressure, there can be no out-rush of thecompressed air from the clearance spaces. This out-rush when permittedis ve ob-, jectionable, since it is desirable that the cylinder shallbegin to fill at an early point in the inlet stroke, and some time isrequired for the ingoing, air to overcome the out-rush of the compressedair; 1

By the valve arrangement shown, avery short movement of the piston onits inlet stroke will expand the .air in the ports 9 to atmosphericpressure, the valves 14 then open-to admit air to the cylinder, and thecylinder fills freely and rapidly. The 'arrangement of the two valves 14at each end of the cylinder practically doubles the inlet area andinsures the flowing in of a 'maximum volume of air.- The inlet valvesre-- main open until the piston reaches the end of its reverse stroke,when they again come to the position shown in Fig. 1,.and shortly afterthe reverse stroke commences, the ports 17 come into line with theports9. The trapped air in the spaces 12 will then escape into the cylinder,and increase the volume of air therein to this extent. When a point isreached in the com ression stroke where the compression is su cient toovercome the pressure, at the dischar e valves 13, these valves openautomatica y. The action of the valves 13 can be readily determined byinspection and their throw determined by measurement of the movement of.the outer ends of the valve rods or stems. If the valves are found to beworking unequally, the plug 28 of any valve can be screwed in or out tochange thetension of the sprin 31 to give the proper'action to thatvalve. he valves 33 and 35 can also be regulated to vary the dash-poteffect in either direction of the piston 30 in the chamber 29. Thisclose adjgustment and regulation of the valves 1s made possible by thefact that the oil groove packing is practically frictionless and doesnot cause the valves to stop in midstroke by bmdmg of a packing. It canbe eflected without stopping the engine and constitutes invention.

. The advantagts of my invention will be readily understood by thoseskilled in the art from the foregoing description. The valve arrangementand movement is extremely simple in its character, and the objects ofthe invention, as heretofore stated, are accom-' be emplo ed.

What

claim is w 1 1. A blowing engine or compressor, having two rota valvesin each of its heads, one at each si e-of the iston rod, said valvesbeing used for both et and discharge, actuatlng connections arranged topositively operate the two .valves in each head simultaneousl and thevalves in the two heads opposite y, and automatic discharge valveslocated in the discharge ports or' passages of the compressor beyond therotary valves; substantlally as described.

2. A blowing engine or compressor, having chambered heads, provided withtransverse partitions forming separate inlet chambers, a port leadingfrom each of said chambers to the cylinder, a rota valve having a seatin each of said ports, t ere being a ischarge port leading fromeachseat, and the one of the many important features of my 1 rotaryvalves havlng both inlet and outlet In hand.

y GEORGE MESTA. Witnesses J. O. HAWLEY, G. E. Tow1-zsmm.

